Contact List - Add a Non-Alpha Character Filter?

In my contact list, I have some company names that begin with digits. The current "Show only contacts beginning with:" filter only lets you choose alphabetic characters from the drop-down list (though I realize you can type in any character directly into the box). It would be useful to include a similar drop-down filter for all non-alpha characters (numbers and various punctuation marks). One filter for all the various non-alpha characters should be sufficient.